One Day musical announces lead casting ahead of world premiere

Exclusive: Co-producers The Royal Lyceum Edinburgh and Melting Pot have announced the principal cast for the world premiere of One Day, a new musical based on David Nicholls’ 2009 novel.

The show is set on St Swithin’s Day (15 July, in fact!) across multiple years as a couple grow from students into adults. It was adapted into a solidly-received film in 2011, followed by a much-loved 2024 Netflix series.

WhatsOnStage and Olivier Award-nominee Jamie Muscato will play Dexter, while Sharon Rose will play Emma. Further casting will be revealed in due course.

The musical is written by David Greig with music and lyrics by Abner and Amanda Ramirez of Johnnyswim and additional material by Freya Catrin Smith. Max Webster directs. The creative team includes Carrie-Anne Ingrouille as choreographer, Rae Smith as set and costume designer, Bruno Poet as lighting designer, Simon Baker as sound designer, Nigel Lilley as music supervisor and arranger, Simon Hale as orchestrator and Stuart Burt as casting director.

One Day opens at The Royal Lyceum Theatre Edinburgh on 27 February 2026, with press night on 11 March. The run continues until 5 April as part of the Lyceum’s 60th anniversary season, the first programmed by new artistic director James Brining.

Check out Muscato’s top three picks in our exclusive video: